Associate
Ok thanks for the info, I won't tinker with pre amps just yet 
*** The DIY Audio Thread ***
- Thread starter -Ad-
- Start date
Bijou is finished
This looks gorgeous mate!
I've been reading this thread and others and have decided to build a CMoy. I have no electronic skills so should be nice gentle start for me.
Soldato
I keep plugging my own Cmoy thread, but seeing as you asked so politely...
http://forums.overclockers.co.uk/showthread.php?t=17860076
http://forums.overclockers.co.uk/showthread.php?t=17860076
Associate
Just read through your thread, seems like you had fun. I have built two CMoy's now based on the basic design from tangentsoft.net. I am thinking of some modifications whilst I am waiting for my bits for my LM1875. What would you recommend? I would like to give the amp more bass, do you reckon the I should up the powersupply caps? Or up the input caps as well?
Associate
- Joined
- 9 Mar 2008
- Posts
- 1,039
The Bijou looks really good Adam!
Thanks to the student loans company, i now have some money, so its time to think about buying some kit! I have been looking at some gainclone sites, as well as DIY audio etc and am interested in building one. A lot of people seem to recommend the 4780 gainclones, so i have been looking primarily at these. I would like to have another stab at the control kit from Dantimax, and convieniently they also sell some gainclone kits. This would obviously save me paying postage twice, and they seem to use quality components, but the power supply is built on to the same board as the amp - i presume that this is not a problem and will not affect sound quality?
I am also a little unsure as to which toroid i should choose. I would like to buy a toroid that would be suitably for tha gainclone, and possibly the amp10/basic in the future. Dantimax sells some suitable models for the gainclone (although i think i would buy from the UK to save on postage) rated at either 2x17 100VA, or 2x22 at 120 and 160 VA - are these suitable for the amp10's?
I have also read about the benefits of a buffer on the front end of some gainclones and its significant effects on sound. Anyone built a gainclone and used a buffer (looking at you damian!
)? Has it made all that much difference to sound quality?
Thanks to the student loans company, i now have some money, so its time to think about buying some kit! I have been looking at some gainclone sites, as well as DIY audio etc and am interested in building one. A lot of people seem to recommend the 4780 gainclones, so i have been looking primarily at these. I would like to have another stab at the control kit from Dantimax, and convieniently they also sell some gainclone kits. This would obviously save me paying postage twice, and they seem to use quality components, but the power supply is built on to the same board as the amp - i presume that this is not a problem and will not affect sound quality?
I am also a little unsure as to which toroid i should choose. I would like to buy a toroid that would be suitably for tha gainclone, and possibly the amp10/basic in the future. Dantimax sells some suitable models for the gainclone (although i think i would buy from the UK to save on postage) rated at either 2x17 100VA, or 2x22 at 120 and 160 VA - are these suitable for the amp10's?
I have also read about the benefits of a buffer on the front end of some gainclones and its significant effects on sound. Anyone built a gainclone and used a buffer (looking at you damian!
)? Has it made all that much difference to sound quality?
Associate
Sorry guys, I am after some more help. I am putting together a new CMoy this time with a buffered powersupply as seen here:
The problem is when I measure V+ and V- with no load I get +/- 8.5V which is fine. But as soon as I plug the headphones into the output jack this changes to +1.5V and -15V or there abouts. Do you have any idea whats going on? I have checked my connections on the jack and re-soldered them
The problem is when I measure V+ and V- with no load I get +/- 8.5V which is fine. But as soon as I plug the headphones into the output jack this changes to +1.5V and -15V or there abouts. Do you have any idea whats going on? I have checked my connections on the jack and re-soldered them
Soldato
Try it without R3 - short it out.
Associate
Sorry should have said, I have not used R3 in my powersupply circuit. Any other ideas?
Soldato
Have you tried the amplifier using a simple rail-splitter power supply first?
Associate
Yes had it working fine using the simple rail splitter. Also tried a different chip in the circuit. The power is fine untill I connect the output jack 
Soldato
All I can suggest is that you double-check your power supply circuit then. Is it exactly as above, but without R3?
Are all your amplifier circuit's ground points definitely connected to the VGND generated by your power supply?
Associate
- Joined
- 9 Mar 2008
- Posts
- 1,039
p4radox - what secondary voltages on the toroid does the amp10/amp10b require?
Soldato
18V to 24V is recommended.
Associate
It is the same but without R3 and a 1000uF cap instead of a 220uF.
I have checked the grounds and they all seems fine. When I listen to the amp the signal is there but very feint, I only here something at full volume. But the voltages get unbalanced as soon as I plug in a load on the output.
Associate
I have also noticed that the drivers in my test headphones (iPod earbuds) are getting hot. Is this because I have to have the volume almost on max just to hear anything through the amp? Or is it that I have an unwanted current somewhere?
Associate
Right got it working! Sorry to waste all of your time guys, I am a ****head. I forgot to break the track under the amp chip!! Working now.
Last edited: